follow Randle sevick equation peak current is proportional with scan rate. physical significance: slow scan rate current is decreased down: mass transfer ion adsorption desorption
The measured current = faradic current (electrode reaction) + capacitive current (double layer charging).
i.i. total current density, J = Jf + Jc = Jf + Cd (dE/dt). Cd is the double layer capacitance, and dE/dt is the scan rate. In conclusion, the current increase due to the increase in the capacitive current as the scan rate increases.
current is a function of concentration which changes with time
we vary potential with time
but when current becomes independent of potetial it is no longer elctrochemically controlled
may be chemical and other non electro chemical porcesses
Q = CV
Differentiate wrt Time
I = C dV/dt
Implies that current is proportional to the rate of change of potential
Higher the rate of change of potential higher the charges that accumulated in small time
So current increases with scan rate
When the scan rate is increased, it refers to the speed at which the potential of the working electrode is changing during a cyclic voltammetry experiment. This change in potential affects both the kinetics and mass transport processes, leading to an increase in current.
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